1. Technical Field
The present invention relates to a display apparatus for displaying an image using a liquid crystal panel, and a control method of the display apparatus.
2. Description of Related Art
In a display apparatus for displaying an image using a liquid crystal panel, a response of a change in brightness may be delayed, and an image quality of a moving image may be deteriorated, according to an amount of change in the brightness of a pixel. For example, a so-called tailing in which a moving object in the moving image is displayed while having a tail occurs. Therefore, in the display apparatus, an overdrive control is performed which controls the liquid crystal panel so as to change the brightness of the pixel by an amount of change so that the response of the change in the brightness becomes faster, and then changing to an intended brightness, and thereby improving the response of the brightness. Japanese Patent Publication No. 4425643 discloses a technique that appropriately determines parameters for the overdrive control.
Conventionally, a vertical alignment (VA) type liquid crystal panel, in which a non-transmission state of light is represented by vertically aligning a liquid crystal with respect to a display surface, and a transmission state of light is represented using a refractive index which is changed by applying a voltage to the liquid crystal to bring down the liquid crystal, is used. In the display apparatus including the VA type liquid crystal panel, there is a problem that the response is delayed when the brightness of the pixel is greatly changed. Therefore, in the display apparatus including the VA type liquid crystal panel, when changing the brightness of the pixel from a minimum value of a displayable brightness to a maximum value thereof or a value near the maximum value, the overdrive control is performed which controls the liquid crystal panel so as to change the brightness of the pixel to a brightness between the minimum value and the brightness to be displayed, and then change to the maximum value or the value near the maximum value. For example, when controlling the brightness by 256 gradations, the liquid crystal panel is controlled so as to change a gradation value representing the brightness of the pixel from a gradation value 0 to a gradation value 244, and then to a gradation value 255.